Thickening of cortex areas implicated in mental illness shows increasing genetic influence as the brain develops in childhood and adolescence, NIMH researchers have found. These areas also happen to be the latest to evolve and the last to mature. The peak of genetic influence in these areas coincides with the typical age-of-onset of most mental disorders in late adolescence/early adulthood. The new findings may provide insight into the workings of gene-by-environment-by age interactions in the disorders, says Jay Giedd, M.D., of the NIMH Child Psychiatry Branch.

Scientists have bioengineered an enhancement to a cutting edge technology that provides instant control over brain circuit activity with a flash of light. The research adds the same level of control over switching neurons off that, until now, had been limited to switching them on. What had been working through a weak pump now works through a highly responsive channel -- like going from a squirt to a gushing hose. Project officer Michelle Freund, Ph.D., of the NIMH Office of Technology Development and Coordination, explains the significance of the new findings.

For more than twenty years, National Institute of Mental Health neuroscientist Dr. Jay Giedd has studied the development of the adolescent brain. Decades of imaging work have led to remarkable insight and a more than a few surprises.